The preparation method of olefin copolymer using a general Ziegler-Natta catalyst or metallocene catalyst is enforced industrial widely.
Specially, in the polymerization process of olefin copolymer commercialized with the Ziegler-Natta catalyst, it is generalized that the Ziegler-Natta catalyst is substituted with the metallocene catalyst in rest times. However, because the contents of water, alcohol, other impurities and the like, are high in the above kinds of preparation process, the activity of the catalyst is decreased, and the physical properties of the olefin copolymer which is produced are deteriorated in the polymerization process.
In order to prevent the above problems, the methods for the materials purification were suggested. However, it is necessary to use expensive equipments in the above methods and the purity of the materials which is refined is not high. Accordingly, it is not enough to apply the above methods to the polymerization process of olefin copolymer.